Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Epi (Elise) > Epi Exam 3 > Flashcards

Epi Exam 3 Flashcards

1
Q

What are the requirements of the Egg Product Inspection Act (EPIA)? What are the roles of the FDA and USDA under this act?

A

Mandatory inspection of eggs and egg products for safety and adulteration
Mandatory pasteurization of egg products

– FDA: safety of shell eggs produced in the USA
– USDA: safety of egg products, imported shell eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

These types of eggs are considered what?

  • Rotten or sour eggs
  • Eggs with very green whites (Pseudomonas)
  • Eggs with stuck yolks (stored too long)
  • Moldy eggs or musty eggs
  • Eggs with blood rings or embryonic chicks
A

inedible eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When washing eggs, what do you want to preserve?

A

the cuticle

Use warm water, mild cleaners, rinse with approved sisinfectant

Do not scrub/spray excessively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are Eggs natural antimicrobial defenses?

A
  • Physical barriers to bacteria entry
    – Eggshell, cuticle, and shell membranes
  • Antimicrobial proteins
    – Lysozyme in albumen
    – IgA and IgMin albumen & IgG in yolk
  • Interior egg pH
    – The pH of newly laid eggs is 7.6-­‐7.9
    – As CO2 is lost during storage, pH may reach 9.7 (hinders growth of spoilage bacteria)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What kind of eggs are theses considered?

  • Contaminated with any unsafe pesticide, food additive, or dye
  • Prepared under unsanitary conditions
  • incubated
  • Damaged (and concealed or misrepresented)
  • modified, substituted, or replaced with anything to “make it appear better or of greater value than it is”
A

Adulterated eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

T/F: By law, egg products must be pasteurized

A

True.

Remember the USDA is responsible for the safety of egg products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Standards for egg quality are all set by the _____ (USDA or FDA)

A

USDA

Quality assurance progams are opional. The EPIA only mandates SAFE and not unhealthy eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Egg-Borne Disease outbreaks are usually cause by which pathogen?

A

Salmonella enterica enterica Enteritidis

They account for the The most common salmonellosis in the USA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which common Egg-Borne pathogen infects the ovaries of healthy-appearing hens and can be transmitted via surface contamination of egg-shells?

A

Salmonella Enteritidis

—————————————————

This pathogen survives, but does not grow, in the refrigerator

Disease in humans is caused by eating raw or undercooked eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are tehe two main ways to prevent Salmonella Enteritis infections?

A
  1. Prevent transmission from eggs - pasteurization and cooking of eggs
  2. Reduce or eliminate “carrier” hens - culling and creation of disease-free flocks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

These are the USA control programs in place for which disease?

  • Biosecurity and pest control
  • Clean and disinfect premises that
    have tested positive before adding disease‐free pullets
  • Procure or raise disease-­‐free pullets to replace “retired” laying hens
  • Perform environmental testing on a regular basis
  • If environmental tests positive, must then test eggs
A

Salmonella Enteritidis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What do you call an excess of cases in a geographic region in a particular group with a change in the amount of disease

A

Outbreak

Usually due to change in environment, host or agent

Individuals in outbreaks share a common (1) Outcome and (2) Exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the 4 goals of outbreak investigations.

A
  1. Characterize the outbreak (descriptive epi)
  2. Identify the causal factors (analytical epi)
  3. Implement cost-­‐effective control/prevention interventions
  4. Evaluate your interventions (analytical epi)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

These are the steps of what process?

  1. Establish that it is an outbreak
  2. Establish a diagnosis
  3. Establish a case definition
  4. Establish the magnitude
  5. Describe the outbreak by individual, place and time
  6. Develop a hypothesis
  7. Test the hypothesis
  8. Design interventions
  9. Evaluate the interventions
A

Outbreak Investigation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the challenges of establishing if there is an outbreak in endemic diseases?

A
  • Requires intensive record keeping
  • Dx labs may be seeing more cases because it is becoming more popular amound profucers and vets (thus they are sending out more samples), and not due to more disease in the population
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the two parts of a good case definition for an outbreak?

A
  1. Specifies characteristics shared by those with the dz
  2. Specifies characteristics that distinguish dzed (cases) from non-­‐dzed (non-­‐cases)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When testing a hypothesis for a Dz outbreak, how should you base yours identification of the most important factors? ( name 3 factors)

A
  1. Biological relevance
  2. Statistical significance
  3. Strength of the association
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the collabortive effort of multple health science professions and environmental experts working together for the Convergence of human, animal, plant health and the health of the environment?

A

One Health

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

t/f: “Almost every human disease can be caused, modified, or altered by an environmental agent”

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the Preservation of Antibiotics for Medical Treatment Act want to inforce?

A

Stop the use of antibiotics in food animals for prophalaxis and growth promotion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What do you call the study of disease in populations?

A

epidemiology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

—Veterinary epidemiology deals with the investigation of what 3 aspects in animal populations

A

Disese

Productivity

Welfare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Compared to the clinical approach, what does success not depend on in the epidemiological approach?

A

Success without knowing the etiological agent

—————————-

Clinical approach- success depends on the correct diagnosis

24
Q

What type of epidemiology describes disease (or other health-­‐related events) by its characteristics, amount and distribution of disease in a specified population (What, Who, When, Where)?

A

Descriptive Epidemiology

25
Q

Which type of epidemiology Determine if there is an association between an exposure and outcome in a population and how strong the association is (Why) with the ultimate goal is to determine if an exposure factor causes the disease?

A

Analytical Epi

26
Q

Does epidemiologu determine the cause or the associations/relationships of a disease?

A

associations/relationships

27
Q

What is Rothman’s model (Causal pies) of disease causation?

A

Disease is caused by multiple factors – when a host is exposed to all these factors (not necessarily at the same time), disease occurs

28
Q

What is the difference between a test value and a test result?

A

Test value= what is measures (ie enzymes, antibodies, metabolites, cells)

Test result= decision made by the test/dignostician to if the test is positive or negative

29
Q

T/F: According to Rothmans model, you can have more than one sufficient cause (“complete pie”) for a single disease

A

True

30
Q

We determine the _____ (of our new test) by using it to
test a group of diseased animals (as determined by the
gold standard test)

–Se or Sp–

A

Sensitivity (se)

31
Q

We determine the______ (of our new test) by using it to test a group of non-­‐diseased animals (as determined by the gold standard test)

–se or sp–

A

specificity (sp)

32
Q

Sensitivity is the proportion of diseased animals that the test correctly classifies as ________

(positive or negative)

A

positive

“remember, we must be sensitive to our diseased animals”

33
Q

What were the two reasons that sensitivity can be low?

A
  • There are very few/small amounts of whatever the test measures
  • —Samples are degraded before testing
34
Q

Specificity is the proportion of non-­‐diseased animals
that the test correctly classifies as ________ (positive or negative)

A

negative

35
Q

t/f: A very s_ensitive test_, when negative, rules disease out
—

A

True

…in other words = SnNOut: Sensitive test, when Negative, rules disease Out

36
Q

T/F: A very specific test, when positive, rules disease in

A

True

SpPIn: Specific test when Positive rules disease In

37
Q

Would you want a test with high sensitivity or high specificity when trying to keep FAD out of a country?

A

high sensitvity

….want to be 100% sure the animal is negative

false positives can be tested with a more specific test

38
Q

When the cost of a false positive is very high (and the cost of false negatives is low), would you want a test with high sensitivity or high specificity?

A

High Specificity

Ex. when compensing owners in a culling program, when diagnosing cancer or other high stress diseases

39
Q

When testing in series, what is the order of test you should preform?

(ie should you have a high sensitivity or a high specigicity test first/second)

A

1st= high sensitivity

2nd= high sepcificity of animals who tested positive on the first test. Removes false positives(FP) and ensures all positives are true positives (TP).

40
Q

T/F: Se and Sp tell you the probability that an animal which tests positive in your clinic is truly diseased

A

False!

They do not tell you the probability, they only tell you how good your test is at identifying positive/negative animals

  • Se is the probability of a diseased animal testing positive
  • —Sp is the probability of a non-­‐diseased animal testing negative

Should use PPV and NPV instead

41
Q

How do you determine the PPV?

A

PPV = # diseased/# test +ve

42
Q

High Specificity test produces:
– _____ true negatives test results
– _____ false positives test results

(Many or Few)

A

High Specificity test produces:
– Many true negatives test results
– Few false positives test results

43
Q

Low Specificity test produces:
– ____true negatives test results
– ____ false positives test results

(Many or Few)

A

Low Specificity test produces:
– Few true negatives test results
– Many false positives test results

44
Q

High Sensitivity test produces:
– _____ true positive test results
– _____ false negative test results

(Many or Few)

A

High Sensitivity test produces:
– Many true positive test results
– Few false negative test results

Remember Sensitivity is measured by testing diseased animals

45
Q

Low Sensitivity test produces:
– ____ true positive test results
– _____ false negative test results

(many or Few)

A

Low Sensitivity test produces:
– Few true positive test results
– Many false negative test results

46
Q

T/F: PPV and NPV change based on the prevelance of the disease in the area

A

True

47
Q

What is R0?

A

basic reproductive number (of an infection in a population)

number of secondary cases generated by a typical infectious individual when the rest of the population is susceptible (i.e. at the start of an outbreak)

R= (average contacts) x (transmission probability) x (Duration of infectivity)

R >1: exponential spread

R=1: consistant in population

R<1 : infection goes extinct

48
Q

What will happen to disease prevelance if the Ro is:

>1 , =1 or <1

A

R0 >1: exponential increase

R0=1: consistant in population

R0<1 : infection goes extinct

49
Q

How can you use the concent of R0 to manage disease?

A
50
Q

How do you determine the vaccination critical threshold of a population for a particular disease?

A

Vc = 1 - (1/R0)

As R0 increase, Vc increases

Ex. R0= 2, Vc= 1 - (1/2) = 50%

R0= 10, Vc​= 1 - (1/10) = 90%

Assumes vaccination is random, there is perfect immunity and the population randomly mixes

51
Q

What assumptions are made when you use the Vc = 1 - (1/R0) to determine a population critical threshold?

A

Assumes vaccination is random, there is perfect immunity and the population randomly mixes

-

52
Q

What is the difference b/w isolation and quarantine?

A

Isolation - sick animals isolated from potential contacts

Quarantine - all animals isolated

53
Q

What consists of the Reed Frost-models or SIR compartment models?

A

Susceptible

Infectious

Removed/Recovered/Resistant

54
Q

What variables do compartment models depend on?

A

Probability of “effective contact“ (P)
—Number of infectious hosts (I / ‘cases’)
Number of susceptible hosts (S)

55
Q

What assumptions are being made when using a compartmental model?

A
  • The population is closed, with no new animals
  • —The probability of “effective contact” is the same for every individual animal
  • —Any susceptible animal has an equal probability of developing the infection
  • —An infectious individual will be infectious to others only within the time period following exposure, then will become “resistant” (or will be “removed, i.e. die)
  • —These conditions remain constant during the epidemic
56
Q

What are ways of managing disease if using a compartmental model?

A

Reduce Susceptibles (S) or Reduse effective contacts (P)

Epi (Elise) (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions